Preparation for arrival of Asian Soybean Rust paid off

You might say the USDA saw it coming. Federal agencies did a mock run-through of responding to Asian soybean rust a little more than a month before the Animal and Plant Health Inspection Service (APHIS) actually confirmed its presence in Louisiana and subsequently in eight other states.

The preparation was fortunate for the nation’s soybean growers.

Beginning as far back as two years ago, the federal department had at least eight agencies working on soybean rust from identification and control, to forecasting and economics, said Burleson Smith, of the USDA Office of the Deputy Secretary. Smith was among the speakers at the recent American Soybean Association’s Soybean Rust Education Meeting in Savannah, Ga.

In the summer of 2002, the USDA met with the American Soybean Association, the United Soybean Board, EPA and CropLife America to map out a strategy. That is when coordination of Section 18 requests with states also began. In addition, experts began comparative efficacy trials in South America under Asian Soybean Rust pressure.

By the fall of 2002, the USDA had some good leads about which fungicides offered control options and for how many acres.

At the time, only two fungicides had registrations for soybean rust. An Economic Research Service study published last year showed the potential first-year damage from soybean rust in the $600,000 to $1.3 billion range.

The Animal and Plant Health Inspection Service came up with a strategic plan that sprang into action this past fall. The disease was put on the list of Biological Agents and Toxins for the Ag Bioterrorism Acts and the National Plant Diagnostic Network worked with 23 states to set up scenarios of how to respond when soybean rust hit the U.S.

Little did the agencies know when they conducted a mock run through on Sept. 4, 2004 in Minnesota just how close they were to the actually thing happening.

“The timing couldn’t have been any better” in order to be prepared to respond quickly, Smith said.

APHIS confirmed soybean rust in Louisiana on Nov. 10, 2004. It likely moved up from Colombia and South America on the winds of hurricanes. By December 2004, APHIS confirmed soybean rust in nine states.

“We found it at the end of the season, and we’ve had this much more time to prepare for the coming season,” Smith said.

Meetings continue, including six sponsored by the American Soybean Association across the country. Other meetings have included ag retailers, crop consultants and organic soybean growers, as well as local and state meetings within individual states. In early February, experts met in Indiana.

“A communication effort is in place to get the information to you as soon as possible,” Smith said.

Already in place is a system for forecasting the risk to an epidemic of soybean rust.

Smith said a forecasting system will be important because every year will be different for soybean rust.

Outside of Asia, before 1995 soybean rust was found only in Africa. Likely hitching a ride on winds, it moved from Africa to South America soon afterwards, causing as much as 40 percent to 80 percent damage to soybean yields in South America.

In 2004, researchers found soybean rust in Colombia.

The disease presents a series of dark, reddish to dark brown spots on the leaves of soybeans. It causes a yellowing before causing the plant to drop its leaves. The spores look like little volcanoes on the leaves. Soybean rust can produce as many as 500 billion spores per acre per day.

The best conditions for its spread include moisture on leaves for six to eight hours and 65 degrees Fahrenheit to 82 degrees Fahrenheit. New spores form in six to 10 days. The disease progresses faster as the crop matures.

It does not over-winter in northern climates. So, it will likely over-winter in south Florida, Texas, Louisiana and Georgia.

In fact, conditions exist 90 percent of the time in the Southeast for “soybean rust to develop in epidemic proportions,” Smith said.

Because of its fast-spreading nature, soybean rust will have to be the target of timely fungicide applications.

“This disease has the potential to be the most destructive disease to soybeans in the U.S.,” says Coanne E. O’Hern of APHIS.

In 2002, there were 72.1 million acres of soybeans in the U.S. An ERS study showed that soybean rust could affect 10 percent of the crop in the first year. That could equate to as much as $1.3 billion.

Over-wintering of soybean rust is possible from early January to mid-March, early-April in Texas, Louisiana, Georgia and Florida.

“By June, we’re all in this together” throughout the U.S., O’Hern says.